xref: /linux/arch/x86/kernel/apic/apic.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 /*
2  *	Local APIC handling, local APIC timers
3  *
4  *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
5  *
6  *	Fixes
7  *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
8  *					thanks to Eric Gilmore
9  *					and Rolf G. Tews
10  *					for testing these extensively.
11  *	Maciej W. Rozycki	:	Various updates and fixes.
12  *	Mikael Pettersson	:	Power Management for UP-APIC.
13  *	Pavel Machek and
14  *	Mikael Pettersson	:	PM converted to driver model.
15  */
16 
17 #include <linux/perf_event.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/mc146818rtc.h>
20 #include <linux/acpi_pmtmr.h>
21 #include <linux/clockchips.h>
22 #include <linux/interrupt.h>
23 #include <linux/bootmem.h>
24 #include <linux/ftrace.h>
25 #include <linux/ioport.h>
26 #include <linux/module.h>
27 #include <linux/sysdev.h>
28 #include <linux/delay.h>
29 #include <linux/timex.h>
30 #include <linux/dmar.h>
31 #include <linux/init.h>
32 #include <linux/cpu.h>
33 #include <linux/dmi.h>
34 #include <linux/nmi.h>
35 #include <linux/smp.h>
36 #include <linux/mm.h>
37 
38 #include <asm/perf_event.h>
39 #include <asm/x86_init.h>
40 #include <asm/pgalloc.h>
41 #include <asm/atomic.h>
42 #include <asm/mpspec.h>
43 #include <asm/i8253.h>
44 #include <asm/i8259.h>
45 #include <asm/proto.h>
46 #include <asm/apic.h>
47 #include <asm/desc.h>
48 #include <asm/hpet.h>
49 #include <asm/idle.h>
50 #include <asm/mtrr.h>
51 #include <asm/smp.h>
52 #include <asm/mce.h>
53 #include <asm/kvm_para.h>
54 
55 unsigned int num_processors;
56 
57 unsigned disabled_cpus __cpuinitdata;
58 
59 /* Processor that is doing the boot up */
60 unsigned int boot_cpu_physical_apicid = -1U;
61 
62 /*
63  * The highest APIC ID seen during enumeration.
64  *
65  * On AMD, this determines the messaging protocol we can use: if all APIC IDs
66  * are in the 0 ... 7 range, then we can use logical addressing which
67  * has some performance advantages (better broadcasting).
68  *
69  * If there's an APIC ID above 8, we use physical addressing.
70  */
71 unsigned int max_physical_apicid;
72 
73 /*
74  * Bitmask of physically existing CPUs:
75  */
76 physid_mask_t phys_cpu_present_map;
77 
78 /*
79  * Map cpu index to physical APIC ID
80  */
81 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
82 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
83 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
84 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
85 
86 #ifdef CONFIG_X86_32
87 /*
88  * Knob to control our willingness to enable the local APIC.
89  *
90  * +1=force-enable
91  */
92 static int force_enable_local_apic;
93 /*
94  * APIC command line parameters
95  */
96 static int __init parse_lapic(char *arg)
97 {
98 	force_enable_local_apic = 1;
99 	return 0;
100 }
101 early_param("lapic", parse_lapic);
102 /* Local APIC was disabled by the BIOS and enabled by the kernel */
103 static int enabled_via_apicbase;
104 
105 /*
106  * Handle interrupt mode configuration register (IMCR).
107  * This register controls whether the interrupt signals
108  * that reach the BSP come from the master PIC or from the
109  * local APIC. Before entering Symmetric I/O Mode, either
110  * the BIOS or the operating system must switch out of
111  * PIC Mode by changing the IMCR.
112  */
113 static inline void imcr_pic_to_apic(void)
114 {
115 	/* select IMCR register */
116 	outb(0x70, 0x22);
117 	/* NMI and 8259 INTR go through APIC */
118 	outb(0x01, 0x23);
119 }
120 
121 static inline void imcr_apic_to_pic(void)
122 {
123 	/* select IMCR register */
124 	outb(0x70, 0x22);
125 	/* NMI and 8259 INTR go directly to BSP */
126 	outb(0x00, 0x23);
127 }
128 #endif
129 
130 #ifdef CONFIG_X86_64
131 static int apic_calibrate_pmtmr __initdata;
132 static __init int setup_apicpmtimer(char *s)
133 {
134 	apic_calibrate_pmtmr = 1;
135 	notsc_setup(NULL);
136 	return 0;
137 }
138 __setup("apicpmtimer", setup_apicpmtimer);
139 #endif
140 
141 int x2apic_mode;
142 #ifdef CONFIG_X86_X2APIC
143 /* x2apic enabled before OS handover */
144 static int x2apic_preenabled;
145 static __init int setup_nox2apic(char *str)
146 {
147 	if (x2apic_enabled()) {
148 		pr_warning("Bios already enabled x2apic, "
149 			   "can't enforce nox2apic");
150 		return 0;
151 	}
152 
153 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
154 	return 0;
155 }
156 early_param("nox2apic", setup_nox2apic);
157 #endif
158 
159 unsigned long mp_lapic_addr;
160 int disable_apic;
161 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
162 static int disable_apic_timer __cpuinitdata;
163 /* Local APIC timer works in C2 */
164 int local_apic_timer_c2_ok;
165 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
166 
167 int first_system_vector = 0xfe;
168 
169 /*
170  * Debug level, exported for io_apic.c
171  */
172 unsigned int apic_verbosity;
173 
174 int pic_mode;
175 
176 /* Have we found an MP table */
177 int smp_found_config;
178 
179 static struct resource lapic_resource = {
180 	.name = "Local APIC",
181 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
182 };
183 
184 static unsigned int calibration_result;
185 
186 static int lapic_next_event(unsigned long delta,
187 			    struct clock_event_device *evt);
188 static void lapic_timer_setup(enum clock_event_mode mode,
189 			      struct clock_event_device *evt);
190 static void lapic_timer_broadcast(const struct cpumask *mask);
191 static void apic_pm_activate(void);
192 
193 /*
194  * The local apic timer can be used for any function which is CPU local.
195  */
196 static struct clock_event_device lapic_clockevent = {
197 	.name		= "lapic",
198 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
199 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
200 	.shift		= 32,
201 	.set_mode	= lapic_timer_setup,
202 	.set_next_event	= lapic_next_event,
203 	.broadcast	= lapic_timer_broadcast,
204 	.rating		= 100,
205 	.irq		= -1,
206 };
207 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
208 
209 static unsigned long apic_phys;
210 
211 /*
212  * Get the LAPIC version
213  */
214 static inline int lapic_get_version(void)
215 {
216 	return GET_APIC_VERSION(apic_read(APIC_LVR));
217 }
218 
219 /*
220  * Check, if the APIC is integrated or a separate chip
221  */
222 static inline int lapic_is_integrated(void)
223 {
224 #ifdef CONFIG_X86_64
225 	return 1;
226 #else
227 	return APIC_INTEGRATED(lapic_get_version());
228 #endif
229 }
230 
231 /*
232  * Check, whether this is a modern or a first generation APIC
233  */
234 static int modern_apic(void)
235 {
236 	/* AMD systems use old APIC versions, so check the CPU */
237 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
238 	    boot_cpu_data.x86 >= 0xf)
239 		return 1;
240 	return lapic_get_version() >= 0x14;
241 }
242 
243 /*
244  * bare function to substitute write operation
245  * and it's _that_ fast :)
246  */
247 static void native_apic_write_dummy(u32 reg, u32 v)
248 {
249 	WARN_ON_ONCE((cpu_has_apic || !disable_apic));
250 }
251 
252 static u32 native_apic_read_dummy(u32 reg)
253 {
254 	WARN_ON_ONCE((cpu_has_apic && !disable_apic));
255 	return 0;
256 }
257 
258 /*
259  * right after this call apic->write/read doesn't do anything
260  * note that there is no restore operation it works one way
261  */
262 void apic_disable(void)
263 {
264 	apic->read = native_apic_read_dummy;
265 	apic->write = native_apic_write_dummy;
266 }
267 
268 void native_apic_wait_icr_idle(void)
269 {
270 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
271 		cpu_relax();
272 }
273 
274 u32 native_safe_apic_wait_icr_idle(void)
275 {
276 	u32 send_status;
277 	int timeout;
278 
279 	timeout = 0;
280 	do {
281 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
282 		if (!send_status)
283 			break;
284 		udelay(100);
285 	} while (timeout++ < 1000);
286 
287 	return send_status;
288 }
289 
290 void native_apic_icr_write(u32 low, u32 id)
291 {
292 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
293 	apic_write(APIC_ICR, low);
294 }
295 
296 u64 native_apic_icr_read(void)
297 {
298 	u32 icr1, icr2;
299 
300 	icr2 = apic_read(APIC_ICR2);
301 	icr1 = apic_read(APIC_ICR);
302 
303 	return icr1 | ((u64)icr2 << 32);
304 }
305 
306 /**
307  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
308  */
309 void __cpuinit enable_NMI_through_LVT0(void)
310 {
311 	unsigned int v;
312 
313 	/* unmask and set to NMI */
314 	v = APIC_DM_NMI;
315 
316 	/* Level triggered for 82489DX (32bit mode) */
317 	if (!lapic_is_integrated())
318 		v |= APIC_LVT_LEVEL_TRIGGER;
319 
320 	apic_write(APIC_LVT0, v);
321 }
322 
323 #ifdef CONFIG_X86_32
324 /**
325  * get_physical_broadcast - Get number of physical broadcast IDs
326  */
327 int get_physical_broadcast(void)
328 {
329 	return modern_apic() ? 0xff : 0xf;
330 }
331 #endif
332 
333 /**
334  * lapic_get_maxlvt - get the maximum number of local vector table entries
335  */
336 int lapic_get_maxlvt(void)
337 {
338 	unsigned int v;
339 
340 	v = apic_read(APIC_LVR);
341 	/*
342 	 * - we always have APIC integrated on 64bit mode
343 	 * - 82489DXs do not report # of LVT entries
344 	 */
345 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
346 }
347 
348 /*
349  * Local APIC timer
350  */
351 
352 /* Clock divisor */
353 #define APIC_DIVISOR 16
354 
355 /*
356  * This function sets up the local APIC timer, with a timeout of
357  * 'clocks' APIC bus clock. During calibration we actually call
358  * this function twice on the boot CPU, once with a bogus timeout
359  * value, second time for real. The other (noncalibrating) CPUs
360  * call this function only once, with the real, calibrated value.
361  *
362  * We do reads before writes even if unnecessary, to get around the
363  * P5 APIC double write bug.
364  */
365 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
366 {
367 	unsigned int lvtt_value, tmp_value;
368 
369 	lvtt_value = LOCAL_TIMER_VECTOR;
370 	if (!oneshot)
371 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
372 	if (!lapic_is_integrated())
373 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
374 
375 	if (!irqen)
376 		lvtt_value |= APIC_LVT_MASKED;
377 
378 	apic_write(APIC_LVTT, lvtt_value);
379 
380 	/*
381 	 * Divide PICLK by 16
382 	 */
383 	tmp_value = apic_read(APIC_TDCR);
384 	apic_write(APIC_TDCR,
385 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
386 		APIC_TDR_DIV_16);
387 
388 	if (!oneshot)
389 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
390 }
391 
392 /*
393  * Setup extended LVT, AMD specific (K8, family 10h)
394  *
395  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
396  * MCE interrupts are supported. Thus MCE offset must be set to 0.
397  *
398  * If mask=1, the LVT entry does not generate interrupts while mask=0
399  * enables the vector. See also the BKDGs.
400  */
401 
402 #define APIC_EILVT_LVTOFF_MCE 0
403 #define APIC_EILVT_LVTOFF_IBS 1
404 
405 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
406 {
407 	unsigned long reg = (lvt_off << 4) + APIC_EILVTn(0);
408 	unsigned int  v   = (mask << 16) | (msg_type << 8) | vector;
409 
410 	apic_write(reg, v);
411 }
412 
413 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
414 {
415 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
416 	return APIC_EILVT_LVTOFF_MCE;
417 }
418 
419 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
420 {
421 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
422 	return APIC_EILVT_LVTOFF_IBS;
423 }
424 EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
425 
426 /*
427  * Program the next event, relative to now
428  */
429 static int lapic_next_event(unsigned long delta,
430 			    struct clock_event_device *evt)
431 {
432 	apic_write(APIC_TMICT, delta);
433 	return 0;
434 }
435 
436 /*
437  * Setup the lapic timer in periodic or oneshot mode
438  */
439 static void lapic_timer_setup(enum clock_event_mode mode,
440 			      struct clock_event_device *evt)
441 {
442 	unsigned long flags;
443 	unsigned int v;
444 
445 	/* Lapic used as dummy for broadcast ? */
446 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
447 		return;
448 
449 	local_irq_save(flags);
450 
451 	switch (mode) {
452 	case CLOCK_EVT_MODE_PERIODIC:
453 	case CLOCK_EVT_MODE_ONESHOT:
454 		__setup_APIC_LVTT(calibration_result,
455 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
456 		break;
457 	case CLOCK_EVT_MODE_UNUSED:
458 	case CLOCK_EVT_MODE_SHUTDOWN:
459 		v = apic_read(APIC_LVTT);
460 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
461 		apic_write(APIC_LVTT, v);
462 		apic_write(APIC_TMICT, 0xffffffff);
463 		break;
464 	case CLOCK_EVT_MODE_RESUME:
465 		/* Nothing to do here */
466 		break;
467 	}
468 
469 	local_irq_restore(flags);
470 }
471 
472 /*
473  * Local APIC timer broadcast function
474  */
475 static void lapic_timer_broadcast(const struct cpumask *mask)
476 {
477 #ifdef CONFIG_SMP
478 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
479 #endif
480 }
481 
482 /*
483  * Setup the local APIC timer for this CPU. Copy the initilized values
484  * of the boot CPU and register the clock event in the framework.
485  */
486 static void __cpuinit setup_APIC_timer(void)
487 {
488 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
489 
490 	if (cpu_has(&current_cpu_data, X86_FEATURE_ARAT)) {
491 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
492 		/* Make LAPIC timer preferrable over percpu HPET */
493 		lapic_clockevent.rating = 150;
494 	}
495 
496 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
497 	levt->cpumask = cpumask_of(smp_processor_id());
498 
499 	clockevents_register_device(levt);
500 }
501 
502 /*
503  * In this functions we calibrate APIC bus clocks to the external timer.
504  *
505  * We want to do the calibration only once since we want to have local timer
506  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
507  * frequency.
508  *
509  * This was previously done by reading the PIT/HPET and waiting for a wrap
510  * around to find out, that a tick has elapsed. I have a box, where the PIT
511  * readout is broken, so it never gets out of the wait loop again. This was
512  * also reported by others.
513  *
514  * Monitoring the jiffies value is inaccurate and the clockevents
515  * infrastructure allows us to do a simple substitution of the interrupt
516  * handler.
517  *
518  * The calibration routine also uses the pm_timer when possible, as the PIT
519  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
520  * back to normal later in the boot process).
521  */
522 
523 #define LAPIC_CAL_LOOPS		(HZ/10)
524 
525 static __initdata int lapic_cal_loops = -1;
526 static __initdata long lapic_cal_t1, lapic_cal_t2;
527 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
528 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
529 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
530 
531 /*
532  * Temporary interrupt handler.
533  */
534 static void __init lapic_cal_handler(struct clock_event_device *dev)
535 {
536 	unsigned long long tsc = 0;
537 	long tapic = apic_read(APIC_TMCCT);
538 	unsigned long pm = acpi_pm_read_early();
539 
540 	if (cpu_has_tsc)
541 		rdtscll(tsc);
542 
543 	switch (lapic_cal_loops++) {
544 	case 0:
545 		lapic_cal_t1 = tapic;
546 		lapic_cal_tsc1 = tsc;
547 		lapic_cal_pm1 = pm;
548 		lapic_cal_j1 = jiffies;
549 		break;
550 
551 	case LAPIC_CAL_LOOPS:
552 		lapic_cal_t2 = tapic;
553 		lapic_cal_tsc2 = tsc;
554 		if (pm < lapic_cal_pm1)
555 			pm += ACPI_PM_OVRRUN;
556 		lapic_cal_pm2 = pm;
557 		lapic_cal_j2 = jiffies;
558 		break;
559 	}
560 }
561 
562 static int __init
563 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
564 {
565 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
566 	const long pm_thresh = pm_100ms / 100;
567 	unsigned long mult;
568 	u64 res;
569 
570 #ifndef CONFIG_X86_PM_TIMER
571 	return -1;
572 #endif
573 
574 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
575 
576 	/* Check, if the PM timer is available */
577 	if (!deltapm)
578 		return -1;
579 
580 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
581 
582 	if (deltapm > (pm_100ms - pm_thresh) &&
583 	    deltapm < (pm_100ms + pm_thresh)) {
584 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
585 		return 0;
586 	}
587 
588 	res = (((u64)deltapm) *  mult) >> 22;
589 	do_div(res, 1000000);
590 	pr_warning("APIC calibration not consistent "
591 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
592 
593 	/* Correct the lapic counter value */
594 	res = (((u64)(*delta)) * pm_100ms);
595 	do_div(res, deltapm);
596 	pr_info("APIC delta adjusted to PM-Timer: "
597 		"%lu (%ld)\n", (unsigned long)res, *delta);
598 	*delta = (long)res;
599 
600 	/* Correct the tsc counter value */
601 	if (cpu_has_tsc) {
602 		res = (((u64)(*deltatsc)) * pm_100ms);
603 		do_div(res, deltapm);
604 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
605 					  "PM-Timer: %lu (%ld) \n",
606 					(unsigned long)res, *deltatsc);
607 		*deltatsc = (long)res;
608 	}
609 
610 	return 0;
611 }
612 
613 static int __init calibrate_APIC_clock(void)
614 {
615 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
616 	void (*real_handler)(struct clock_event_device *dev);
617 	unsigned long deltaj;
618 	long delta, deltatsc;
619 	int pm_referenced = 0;
620 
621 	local_irq_disable();
622 
623 	/* Replace the global interrupt handler */
624 	real_handler = global_clock_event->event_handler;
625 	global_clock_event->event_handler = lapic_cal_handler;
626 
627 	/*
628 	 * Setup the APIC counter to maximum. There is no way the lapic
629 	 * can underflow in the 100ms detection time frame
630 	 */
631 	__setup_APIC_LVTT(0xffffffff, 0, 0);
632 
633 	/* Let the interrupts run */
634 	local_irq_enable();
635 
636 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
637 		cpu_relax();
638 
639 	local_irq_disable();
640 
641 	/* Restore the real event handler */
642 	global_clock_event->event_handler = real_handler;
643 
644 	/* Build delta t1-t2 as apic timer counts down */
645 	delta = lapic_cal_t1 - lapic_cal_t2;
646 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
647 
648 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
649 
650 	/* we trust the PM based calibration if possible */
651 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
652 					&delta, &deltatsc);
653 
654 	/* Calculate the scaled math multiplication factor */
655 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
656 				       lapic_clockevent.shift);
657 	lapic_clockevent.max_delta_ns =
658 		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
659 	lapic_clockevent.min_delta_ns =
660 		clockevent_delta2ns(0xF, &lapic_clockevent);
661 
662 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
663 
664 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
665 	apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult);
666 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
667 		    calibration_result);
668 
669 	if (cpu_has_tsc) {
670 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
671 			    "%ld.%04ld MHz.\n",
672 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
673 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
674 	}
675 
676 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
677 		    "%u.%04u MHz.\n",
678 		    calibration_result / (1000000 / HZ),
679 		    calibration_result % (1000000 / HZ));
680 
681 	/*
682 	 * Do a sanity check on the APIC calibration result
683 	 */
684 	if (calibration_result < (1000000 / HZ)) {
685 		local_irq_enable();
686 		pr_warning("APIC frequency too slow, disabling apic timer\n");
687 		return -1;
688 	}
689 
690 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
691 
692 	/*
693 	 * PM timer calibration failed or not turned on
694 	 * so lets try APIC timer based calibration
695 	 */
696 	if (!pm_referenced) {
697 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
698 
699 		/*
700 		 * Setup the apic timer manually
701 		 */
702 		levt->event_handler = lapic_cal_handler;
703 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
704 		lapic_cal_loops = -1;
705 
706 		/* Let the interrupts run */
707 		local_irq_enable();
708 
709 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
710 			cpu_relax();
711 
712 		/* Stop the lapic timer */
713 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
714 
715 		/* Jiffies delta */
716 		deltaj = lapic_cal_j2 - lapic_cal_j1;
717 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
718 
719 		/* Check, if the jiffies result is consistent */
720 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
721 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
722 		else
723 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
724 	} else
725 		local_irq_enable();
726 
727 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
728 		pr_warning("APIC timer disabled due to verification failure\n");
729 			return -1;
730 	}
731 
732 	return 0;
733 }
734 
735 /*
736  * Setup the boot APIC
737  *
738  * Calibrate and verify the result.
739  */
740 void __init setup_boot_APIC_clock(void)
741 {
742 	/*
743 	 * The local apic timer can be disabled via the kernel
744 	 * commandline or from the CPU detection code. Register the lapic
745 	 * timer as a dummy clock event source on SMP systems, so the
746 	 * broadcast mechanism is used. On UP systems simply ignore it.
747 	 */
748 	if (disable_apic_timer) {
749 		pr_info("Disabling APIC timer\n");
750 		/* No broadcast on UP ! */
751 		if (num_possible_cpus() > 1) {
752 			lapic_clockevent.mult = 1;
753 			setup_APIC_timer();
754 		}
755 		return;
756 	}
757 
758 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
759 		    "calibrating APIC timer ...\n");
760 
761 	if (calibrate_APIC_clock()) {
762 		/* No broadcast on UP ! */
763 		if (num_possible_cpus() > 1)
764 			setup_APIC_timer();
765 		return;
766 	}
767 
768 	/*
769 	 * If nmi_watchdog is set to IO_APIC, we need the
770 	 * PIT/HPET going.  Otherwise register lapic as a dummy
771 	 * device.
772 	 */
773 	if (nmi_watchdog != NMI_IO_APIC)
774 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
775 	else
776 		pr_warning("APIC timer registered as dummy,"
777 			" due to nmi_watchdog=%d!\n", nmi_watchdog);
778 
779 	/* Setup the lapic or request the broadcast */
780 	setup_APIC_timer();
781 }
782 
783 void __cpuinit setup_secondary_APIC_clock(void)
784 {
785 	setup_APIC_timer();
786 }
787 
788 /*
789  * The guts of the apic timer interrupt
790  */
791 static void local_apic_timer_interrupt(void)
792 {
793 	int cpu = smp_processor_id();
794 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
795 
796 	/*
797 	 * Normally we should not be here till LAPIC has been initialized but
798 	 * in some cases like kdump, its possible that there is a pending LAPIC
799 	 * timer interrupt from previous kernel's context and is delivered in
800 	 * new kernel the moment interrupts are enabled.
801 	 *
802 	 * Interrupts are enabled early and LAPIC is setup much later, hence
803 	 * its possible that when we get here evt->event_handler is NULL.
804 	 * Check for event_handler being NULL and discard the interrupt as
805 	 * spurious.
806 	 */
807 	if (!evt->event_handler) {
808 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
809 		/* Switch it off */
810 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
811 		return;
812 	}
813 
814 	/*
815 	 * the NMI deadlock-detector uses this.
816 	 */
817 	inc_irq_stat(apic_timer_irqs);
818 
819 	evt->event_handler(evt);
820 }
821 
822 /*
823  * Local APIC timer interrupt. This is the most natural way for doing
824  * local interrupts, but local timer interrupts can be emulated by
825  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
826  *
827  * [ if a single-CPU system runs an SMP kernel then we call the local
828  *   interrupt as well. Thus we cannot inline the local irq ... ]
829  */
830 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
831 {
832 	struct pt_regs *old_regs = set_irq_regs(regs);
833 
834 	/*
835 	 * NOTE! We'd better ACK the irq immediately,
836 	 * because timer handling can be slow.
837 	 */
838 	ack_APIC_irq();
839 	/*
840 	 * update_process_times() expects us to have done irq_enter().
841 	 * Besides, if we don't timer interrupts ignore the global
842 	 * interrupt lock, which is the WrongThing (tm) to do.
843 	 */
844 	exit_idle();
845 	irq_enter();
846 	local_apic_timer_interrupt();
847 	irq_exit();
848 
849 	set_irq_regs(old_regs);
850 }
851 
852 int setup_profiling_timer(unsigned int multiplier)
853 {
854 	return -EINVAL;
855 }
856 
857 /*
858  * Local APIC start and shutdown
859  */
860 
861 /**
862  * clear_local_APIC - shutdown the local APIC
863  *
864  * This is called, when a CPU is disabled and before rebooting, so the state of
865  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
866  * leftovers during boot.
867  */
868 void clear_local_APIC(void)
869 {
870 	int maxlvt;
871 	u32 v;
872 
873 	/* APIC hasn't been mapped yet */
874 	if (!x2apic_mode && !apic_phys)
875 		return;
876 
877 	maxlvt = lapic_get_maxlvt();
878 	/*
879 	 * Masking an LVT entry can trigger a local APIC error
880 	 * if the vector is zero. Mask LVTERR first to prevent this.
881 	 */
882 	if (maxlvt >= 3) {
883 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
884 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
885 	}
886 	/*
887 	 * Careful: we have to set masks only first to deassert
888 	 * any level-triggered sources.
889 	 */
890 	v = apic_read(APIC_LVTT);
891 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
892 	v = apic_read(APIC_LVT0);
893 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
894 	v = apic_read(APIC_LVT1);
895 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
896 	if (maxlvt >= 4) {
897 		v = apic_read(APIC_LVTPC);
898 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
899 	}
900 
901 	/* lets not touch this if we didn't frob it */
902 #ifdef CONFIG_X86_THERMAL_VECTOR
903 	if (maxlvt >= 5) {
904 		v = apic_read(APIC_LVTTHMR);
905 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
906 	}
907 #endif
908 #ifdef CONFIG_X86_MCE_INTEL
909 	if (maxlvt >= 6) {
910 		v = apic_read(APIC_LVTCMCI);
911 		if (!(v & APIC_LVT_MASKED))
912 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
913 	}
914 #endif
915 
916 	/*
917 	 * Clean APIC state for other OSs:
918 	 */
919 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
920 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
921 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
922 	if (maxlvt >= 3)
923 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
924 	if (maxlvt >= 4)
925 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
926 
927 	/* Integrated APIC (!82489DX) ? */
928 	if (lapic_is_integrated()) {
929 		if (maxlvt > 3)
930 			/* Clear ESR due to Pentium errata 3AP and 11AP */
931 			apic_write(APIC_ESR, 0);
932 		apic_read(APIC_ESR);
933 	}
934 }
935 
936 /**
937  * disable_local_APIC - clear and disable the local APIC
938  */
939 void disable_local_APIC(void)
940 {
941 	unsigned int value;
942 
943 	/* APIC hasn't been mapped yet */
944 	if (!apic_phys)
945 		return;
946 
947 	clear_local_APIC();
948 
949 	/*
950 	 * Disable APIC (implies clearing of registers
951 	 * for 82489DX!).
952 	 */
953 	value = apic_read(APIC_SPIV);
954 	value &= ~APIC_SPIV_APIC_ENABLED;
955 	apic_write(APIC_SPIV, value);
956 
957 #ifdef CONFIG_X86_32
958 	/*
959 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
960 	 * restore the disabled state.
961 	 */
962 	if (enabled_via_apicbase) {
963 		unsigned int l, h;
964 
965 		rdmsr(MSR_IA32_APICBASE, l, h);
966 		l &= ~MSR_IA32_APICBASE_ENABLE;
967 		wrmsr(MSR_IA32_APICBASE, l, h);
968 	}
969 #endif
970 }
971 
972 /*
973  * If Linux enabled the LAPIC against the BIOS default disable it down before
974  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
975  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
976  * for the case where Linux didn't enable the LAPIC.
977  */
978 void lapic_shutdown(void)
979 {
980 	unsigned long flags;
981 
982 	if (!cpu_has_apic && !apic_from_smp_config())
983 		return;
984 
985 	local_irq_save(flags);
986 
987 #ifdef CONFIG_X86_32
988 	if (!enabled_via_apicbase)
989 		clear_local_APIC();
990 	else
991 #endif
992 		disable_local_APIC();
993 
994 
995 	local_irq_restore(flags);
996 }
997 
998 /*
999  * This is to verify that we're looking at a real local APIC.
1000  * Check these against your board if the CPUs aren't getting
1001  * started for no apparent reason.
1002  */
1003 int __init verify_local_APIC(void)
1004 {
1005 	unsigned int reg0, reg1;
1006 
1007 	/*
1008 	 * The version register is read-only in a real APIC.
1009 	 */
1010 	reg0 = apic_read(APIC_LVR);
1011 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1012 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1013 	reg1 = apic_read(APIC_LVR);
1014 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1015 
1016 	/*
1017 	 * The two version reads above should print the same
1018 	 * numbers.  If the second one is different, then we
1019 	 * poke at a non-APIC.
1020 	 */
1021 	if (reg1 != reg0)
1022 		return 0;
1023 
1024 	/*
1025 	 * Check if the version looks reasonably.
1026 	 */
1027 	reg1 = GET_APIC_VERSION(reg0);
1028 	if (reg1 == 0x00 || reg1 == 0xff)
1029 		return 0;
1030 	reg1 = lapic_get_maxlvt();
1031 	if (reg1 < 0x02 || reg1 == 0xff)
1032 		return 0;
1033 
1034 	/*
1035 	 * The ID register is read/write in a real APIC.
1036 	 */
1037 	reg0 = apic_read(APIC_ID);
1038 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1039 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1040 	reg1 = apic_read(APIC_ID);
1041 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1042 	apic_write(APIC_ID, reg0);
1043 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1044 		return 0;
1045 
1046 	/*
1047 	 * The next two are just to see if we have sane values.
1048 	 * They're only really relevant if we're in Virtual Wire
1049 	 * compatibility mode, but most boxes are anymore.
1050 	 */
1051 	reg0 = apic_read(APIC_LVT0);
1052 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1053 	reg1 = apic_read(APIC_LVT1);
1054 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1055 
1056 	return 1;
1057 }
1058 
1059 /**
1060  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1061  */
1062 void __init sync_Arb_IDs(void)
1063 {
1064 	/*
1065 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1066 	 * needed on AMD.
1067 	 */
1068 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1069 		return;
1070 
1071 	/*
1072 	 * Wait for idle.
1073 	 */
1074 	apic_wait_icr_idle();
1075 
1076 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1077 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1078 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1079 }
1080 
1081 /*
1082  * An initial setup of the virtual wire mode.
1083  */
1084 void __init init_bsp_APIC(void)
1085 {
1086 	unsigned int value;
1087 
1088 	/*
1089 	 * Don't do the setup now if we have a SMP BIOS as the
1090 	 * through-I/O-APIC virtual wire mode might be active.
1091 	 */
1092 	if (smp_found_config || !cpu_has_apic)
1093 		return;
1094 
1095 	/*
1096 	 * Do not trust the local APIC being empty at bootup.
1097 	 */
1098 	clear_local_APIC();
1099 
1100 	/*
1101 	 * Enable APIC.
1102 	 */
1103 	value = apic_read(APIC_SPIV);
1104 	value &= ~APIC_VECTOR_MASK;
1105 	value |= APIC_SPIV_APIC_ENABLED;
1106 
1107 #ifdef CONFIG_X86_32
1108 	/* This bit is reserved on P4/Xeon and should be cleared */
1109 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1110 	    (boot_cpu_data.x86 == 15))
1111 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1112 	else
1113 #endif
1114 		value |= APIC_SPIV_FOCUS_DISABLED;
1115 	value |= SPURIOUS_APIC_VECTOR;
1116 	apic_write(APIC_SPIV, value);
1117 
1118 	/*
1119 	 * Set up the virtual wire mode.
1120 	 */
1121 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1122 	value = APIC_DM_NMI;
1123 	if (!lapic_is_integrated())		/* 82489DX */
1124 		value |= APIC_LVT_LEVEL_TRIGGER;
1125 	apic_write(APIC_LVT1, value);
1126 }
1127 
1128 static void __cpuinit lapic_setup_esr(void)
1129 {
1130 	unsigned int oldvalue, value, maxlvt;
1131 
1132 	if (!lapic_is_integrated()) {
1133 		pr_info("No ESR for 82489DX.\n");
1134 		return;
1135 	}
1136 
1137 	if (apic->disable_esr) {
1138 		/*
1139 		 * Something untraceable is creating bad interrupts on
1140 		 * secondary quads ... for the moment, just leave the
1141 		 * ESR disabled - we can't do anything useful with the
1142 		 * errors anyway - mbligh
1143 		 */
1144 		pr_info("Leaving ESR disabled.\n");
1145 		return;
1146 	}
1147 
1148 	maxlvt = lapic_get_maxlvt();
1149 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1150 		apic_write(APIC_ESR, 0);
1151 	oldvalue = apic_read(APIC_ESR);
1152 
1153 	/* enables sending errors */
1154 	value = ERROR_APIC_VECTOR;
1155 	apic_write(APIC_LVTERR, value);
1156 
1157 	/*
1158 	 * spec says clear errors after enabling vector.
1159 	 */
1160 	if (maxlvt > 3)
1161 		apic_write(APIC_ESR, 0);
1162 	value = apic_read(APIC_ESR);
1163 	if (value != oldvalue)
1164 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1165 			"vector: 0x%08x  after: 0x%08x\n",
1166 			oldvalue, value);
1167 }
1168 
1169 
1170 /**
1171  * setup_local_APIC - setup the local APIC
1172  */
1173 void __cpuinit setup_local_APIC(void)
1174 {
1175 	unsigned int value;
1176 	int i, j;
1177 
1178 	if (disable_apic) {
1179 		arch_disable_smp_support();
1180 		return;
1181 	}
1182 
1183 #ifdef CONFIG_X86_32
1184 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1185 	if (lapic_is_integrated() && apic->disable_esr) {
1186 		apic_write(APIC_ESR, 0);
1187 		apic_write(APIC_ESR, 0);
1188 		apic_write(APIC_ESR, 0);
1189 		apic_write(APIC_ESR, 0);
1190 	}
1191 #endif
1192 	perf_events_lapic_init();
1193 
1194 	preempt_disable();
1195 
1196 	/*
1197 	 * Double-check whether this APIC is really registered.
1198 	 * This is meaningless in clustered apic mode, so we skip it.
1199 	 */
1200 	BUG_ON(!apic->apic_id_registered());
1201 
1202 	/*
1203 	 * Intel recommends to set DFR, LDR and TPR before enabling
1204 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1205 	 * document number 292116).  So here it goes...
1206 	 */
1207 	apic->init_apic_ldr();
1208 
1209 	/*
1210 	 * Set Task Priority to 'accept all'. We never change this
1211 	 * later on.
1212 	 */
1213 	value = apic_read(APIC_TASKPRI);
1214 	value &= ~APIC_TPRI_MASK;
1215 	apic_write(APIC_TASKPRI, value);
1216 
1217 	/*
1218 	 * After a crash, we no longer service the interrupts and a pending
1219 	 * interrupt from previous kernel might still have ISR bit set.
1220 	 *
1221 	 * Most probably by now CPU has serviced that pending interrupt and
1222 	 * it might not have done the ack_APIC_irq() because it thought,
1223 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1224 	 * does not clear the ISR bit and cpu thinks it has already serivced
1225 	 * the interrupt. Hence a vector might get locked. It was noticed
1226 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1227 	 */
1228 	for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1229 		value = apic_read(APIC_ISR + i*0x10);
1230 		for (j = 31; j >= 0; j--) {
1231 			if (value & (1<<j))
1232 				ack_APIC_irq();
1233 		}
1234 	}
1235 
1236 	/*
1237 	 * Now that we are all set up, enable the APIC
1238 	 */
1239 	value = apic_read(APIC_SPIV);
1240 	value &= ~APIC_VECTOR_MASK;
1241 	/*
1242 	 * Enable APIC
1243 	 */
1244 	value |= APIC_SPIV_APIC_ENABLED;
1245 
1246 #ifdef CONFIG_X86_32
1247 	/*
1248 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1249 	 * certain networking cards. If high frequency interrupts are
1250 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1251 	 * entry is masked/unmasked at a high rate as well then sooner or
1252 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1253 	 * from the device. If focus CPU is disabled then the hang goes
1254 	 * away, oh well :-(
1255 	 *
1256 	 * [ This bug can be reproduced easily with a level-triggered
1257 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1258 	 *   BX chipset. ]
1259 	 */
1260 	/*
1261 	 * Actually disabling the focus CPU check just makes the hang less
1262 	 * frequent as it makes the interrupt distributon model be more
1263 	 * like LRU than MRU (the short-term load is more even across CPUs).
1264 	 * See also the comment in end_level_ioapic_irq().  --macro
1265 	 */
1266 
1267 	/*
1268 	 * - enable focus processor (bit==0)
1269 	 * - 64bit mode always use processor focus
1270 	 *   so no need to set it
1271 	 */
1272 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1273 #endif
1274 
1275 	/*
1276 	 * Set spurious IRQ vector
1277 	 */
1278 	value |= SPURIOUS_APIC_VECTOR;
1279 	apic_write(APIC_SPIV, value);
1280 
1281 	/*
1282 	 * Set up LVT0, LVT1:
1283 	 *
1284 	 * set up through-local-APIC on the BP's LINT0. This is not
1285 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1286 	 * we delegate interrupts to the 8259A.
1287 	 */
1288 	/*
1289 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1290 	 */
1291 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1292 	if (!smp_processor_id() && (pic_mode || !value)) {
1293 		value = APIC_DM_EXTINT;
1294 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
1295 				smp_processor_id());
1296 	} else {
1297 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1298 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
1299 				smp_processor_id());
1300 	}
1301 	apic_write(APIC_LVT0, value);
1302 
1303 	/*
1304 	 * only the BP should see the LINT1 NMI signal, obviously.
1305 	 */
1306 	if (!smp_processor_id())
1307 		value = APIC_DM_NMI;
1308 	else
1309 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1310 	if (!lapic_is_integrated())		/* 82489DX */
1311 		value |= APIC_LVT_LEVEL_TRIGGER;
1312 	apic_write(APIC_LVT1, value);
1313 
1314 	preempt_enable();
1315 
1316 #ifdef CONFIG_X86_MCE_INTEL
1317 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1318 	if (smp_processor_id() == 0)
1319 		cmci_recheck();
1320 #endif
1321 }
1322 
1323 void __cpuinit end_local_APIC_setup(void)
1324 {
1325 	lapic_setup_esr();
1326 
1327 #ifdef CONFIG_X86_32
1328 	{
1329 		unsigned int value;
1330 		/* Disable the local apic timer */
1331 		value = apic_read(APIC_LVTT);
1332 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1333 		apic_write(APIC_LVTT, value);
1334 	}
1335 #endif
1336 
1337 	setup_apic_nmi_watchdog(NULL);
1338 	apic_pm_activate();
1339 }
1340 
1341 #ifdef CONFIG_X86_X2APIC
1342 void check_x2apic(void)
1343 {
1344 	if (x2apic_enabled()) {
1345 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1346 		x2apic_preenabled = x2apic_mode = 1;
1347 	}
1348 }
1349 
1350 void enable_x2apic(void)
1351 {
1352 	int msr, msr2;
1353 
1354 	if (!x2apic_mode)
1355 		return;
1356 
1357 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1358 	if (!(msr & X2APIC_ENABLE)) {
1359 		pr_info("Enabling x2apic\n");
1360 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1361 	}
1362 }
1363 #endif /* CONFIG_X86_X2APIC */
1364 
1365 int __init enable_IR(void)
1366 {
1367 #ifdef CONFIG_INTR_REMAP
1368 	if (!intr_remapping_supported()) {
1369 		pr_debug("intr-remapping not supported\n");
1370 		return 0;
1371 	}
1372 
1373 	if (!x2apic_preenabled && skip_ioapic_setup) {
1374 		pr_info("Skipped enabling intr-remap because of skipping "
1375 			"io-apic setup\n");
1376 		return 0;
1377 	}
1378 
1379 	if (enable_intr_remapping(x2apic_supported()))
1380 		return 0;
1381 
1382 	pr_info("Enabled Interrupt-remapping\n");
1383 
1384 	return 1;
1385 
1386 #endif
1387 	return 0;
1388 }
1389 
1390 void __init enable_IR_x2apic(void)
1391 {
1392 	unsigned long flags;
1393 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1394 	int ret, x2apic_enabled = 0;
1395 	int dmar_table_init_ret = 0;
1396 
1397 #ifdef CONFIG_INTR_REMAP
1398 	dmar_table_init_ret = dmar_table_init();
1399 	if (dmar_table_init_ret)
1400 		pr_debug("dmar_table_init() failed with %d:\n",
1401 				dmar_table_init_ret);
1402 #endif
1403 
1404 	ioapic_entries = alloc_ioapic_entries();
1405 	if (!ioapic_entries) {
1406 		pr_err("Allocate ioapic_entries failed\n");
1407 		goto out;
1408 	}
1409 
1410 	ret = save_IO_APIC_setup(ioapic_entries);
1411 	if (ret) {
1412 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1413 		goto out;
1414 	}
1415 
1416 	local_irq_save(flags);
1417 	mask_8259A();
1418 	mask_IO_APIC_setup(ioapic_entries);
1419 
1420 	if (dmar_table_init_ret)
1421 		ret = 0;
1422 	else
1423 		ret = enable_IR();
1424 
1425 	if (!ret) {
1426 		/* IR is required if there is APIC ID > 255 even when running
1427 		 * under KVM
1428 		 */
1429 		if (max_physical_apicid > 255 || !kvm_para_available())
1430 			goto nox2apic;
1431 		/*
1432 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1433 		 * only in physical mode
1434 		 */
1435 		x2apic_force_phys();
1436 	}
1437 
1438 	x2apic_enabled = 1;
1439 
1440 	if (x2apic_supported() && !x2apic_mode) {
1441 		x2apic_mode = 1;
1442 		enable_x2apic();
1443 		pr_info("Enabled x2apic\n");
1444 	}
1445 
1446 nox2apic:
1447 	if (!ret) /* IR enabling failed */
1448 		restore_IO_APIC_setup(ioapic_entries);
1449 	unmask_8259A();
1450 	local_irq_restore(flags);
1451 
1452 out:
1453 	if (ioapic_entries)
1454 		free_ioapic_entries(ioapic_entries);
1455 
1456 	if (x2apic_enabled)
1457 		return;
1458 
1459 	if (x2apic_preenabled)
1460 		panic("x2apic: enabled by BIOS but kernel init failed.");
1461 	else if (cpu_has_x2apic)
1462 		pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1463 }
1464 
1465 #ifdef CONFIG_X86_64
1466 /*
1467  * Detect and enable local APICs on non-SMP boards.
1468  * Original code written by Keir Fraser.
1469  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1470  * not correctly set up (usually the APIC timer won't work etc.)
1471  */
1472 static int __init detect_init_APIC(void)
1473 {
1474 	if (!cpu_has_apic) {
1475 		pr_info("No local APIC present\n");
1476 		return -1;
1477 	}
1478 
1479 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1480 	return 0;
1481 }
1482 #else
1483 /*
1484  * Detect and initialize APIC
1485  */
1486 static int __init detect_init_APIC(void)
1487 {
1488 	u32 h, l, features;
1489 
1490 	/* Disabled by kernel option? */
1491 	if (disable_apic)
1492 		return -1;
1493 
1494 	switch (boot_cpu_data.x86_vendor) {
1495 	case X86_VENDOR_AMD:
1496 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1497 		    (boot_cpu_data.x86 >= 15))
1498 			break;
1499 		goto no_apic;
1500 	case X86_VENDOR_INTEL:
1501 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1502 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1503 			break;
1504 		goto no_apic;
1505 	default:
1506 		goto no_apic;
1507 	}
1508 
1509 	if (!cpu_has_apic) {
1510 		/*
1511 		 * Over-ride BIOS and try to enable the local APIC only if
1512 		 * "lapic" specified.
1513 		 */
1514 		if (!force_enable_local_apic) {
1515 			pr_info("Local APIC disabled by BIOS -- "
1516 				"you can enable it with \"lapic\"\n");
1517 			return -1;
1518 		}
1519 		/*
1520 		 * Some BIOSes disable the local APIC in the APIC_BASE
1521 		 * MSR. This can only be done in software for Intel P6 or later
1522 		 * and AMD K7 (Model > 1) or later.
1523 		 */
1524 		rdmsr(MSR_IA32_APICBASE, l, h);
1525 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1526 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1527 			l &= ~MSR_IA32_APICBASE_BASE;
1528 			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1529 			wrmsr(MSR_IA32_APICBASE, l, h);
1530 			enabled_via_apicbase = 1;
1531 		}
1532 	}
1533 	/*
1534 	 * The APIC feature bit should now be enabled
1535 	 * in `cpuid'
1536 	 */
1537 	features = cpuid_edx(1);
1538 	if (!(features & (1 << X86_FEATURE_APIC))) {
1539 		pr_warning("Could not enable APIC!\n");
1540 		return -1;
1541 	}
1542 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1543 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1544 
1545 	/* The BIOS may have set up the APIC at some other address */
1546 	rdmsr(MSR_IA32_APICBASE, l, h);
1547 	if (l & MSR_IA32_APICBASE_ENABLE)
1548 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1549 
1550 	pr_info("Found and enabled local APIC!\n");
1551 
1552 	apic_pm_activate();
1553 
1554 	return 0;
1555 
1556 no_apic:
1557 	pr_info("No local APIC present or hardware disabled\n");
1558 	return -1;
1559 }
1560 #endif
1561 
1562 #ifdef CONFIG_X86_64
1563 void __init early_init_lapic_mapping(void)
1564 {
1565 	/*
1566 	 * If no local APIC can be found then go out
1567 	 * : it means there is no mpatable and MADT
1568 	 */
1569 	if (!smp_found_config)
1570 		return;
1571 
1572 	set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
1573 	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1574 		    APIC_BASE, mp_lapic_addr);
1575 
1576 	/*
1577 	 * Fetch the APIC ID of the BSP in case we have a
1578 	 * default configuration (or the MP table is broken).
1579 	 */
1580 	boot_cpu_physical_apicid = read_apic_id();
1581 }
1582 #endif
1583 
1584 /**
1585  * init_apic_mappings - initialize APIC mappings
1586  */
1587 void __init init_apic_mappings(void)
1588 {
1589 	unsigned int new_apicid;
1590 
1591 	if (x2apic_mode) {
1592 		boot_cpu_physical_apicid = read_apic_id();
1593 		return;
1594 	}
1595 
1596 	/* If no local APIC can be found return early */
1597 	if (!smp_found_config && detect_init_APIC()) {
1598 		/* lets NOP'ify apic operations */
1599 		pr_info("APIC: disable apic facility\n");
1600 		apic_disable();
1601 	} else {
1602 		apic_phys = mp_lapic_addr;
1603 
1604 		/*
1605 		 * acpi lapic path already maps that address in
1606 		 * acpi_register_lapic_address()
1607 		 */
1608 		if (!acpi_lapic)
1609 			set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1610 
1611 		apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
1612 					APIC_BASE, apic_phys);
1613 	}
1614 
1615 	/*
1616 	 * Fetch the APIC ID of the BSP in case we have a
1617 	 * default configuration (or the MP table is broken).
1618 	 */
1619 	new_apicid = read_apic_id();
1620 	if (boot_cpu_physical_apicid != new_apicid) {
1621 		boot_cpu_physical_apicid = new_apicid;
1622 		/*
1623 		 * yeah -- we lie about apic_version
1624 		 * in case if apic was disabled via boot option
1625 		 * but it's not a problem for SMP compiled kernel
1626 		 * since smp_sanity_check is prepared for such a case
1627 		 * and disable smp mode
1628 		 */
1629 		apic_version[new_apicid] =
1630 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1631 	}
1632 }
1633 
1634 /*
1635  * This initializes the IO-APIC and APIC hardware if this is
1636  * a UP kernel.
1637  */
1638 int apic_version[MAX_APICS];
1639 
1640 int __init APIC_init_uniprocessor(void)
1641 {
1642 	if (disable_apic) {
1643 		pr_info("Apic disabled\n");
1644 		return -1;
1645 	}
1646 #ifdef CONFIG_X86_64
1647 	if (!cpu_has_apic) {
1648 		disable_apic = 1;
1649 		pr_info("Apic disabled by BIOS\n");
1650 		return -1;
1651 	}
1652 #else
1653 	if (!smp_found_config && !cpu_has_apic)
1654 		return -1;
1655 
1656 	/*
1657 	 * Complain if the BIOS pretends there is one.
1658 	 */
1659 	if (!cpu_has_apic &&
1660 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1661 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1662 			boot_cpu_physical_apicid);
1663 		return -1;
1664 	}
1665 #endif
1666 
1667 	enable_IR_x2apic();
1668 #ifdef CONFIG_X86_64
1669 	default_setup_apic_routing();
1670 #endif
1671 
1672 	verify_local_APIC();
1673 	connect_bsp_APIC();
1674 
1675 #ifdef CONFIG_X86_64
1676 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1677 #else
1678 	/*
1679 	 * Hack: In case of kdump, after a crash, kernel might be booting
1680 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1681 	 * might be zero if read from MP tables. Get it from LAPIC.
1682 	 */
1683 # ifdef CONFIG_CRASH_DUMP
1684 	boot_cpu_physical_apicid = read_apic_id();
1685 # endif
1686 #endif
1687 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1688 	setup_local_APIC();
1689 
1690 #ifdef CONFIG_X86_IO_APIC
1691 	/*
1692 	 * Now enable IO-APICs, actually call clear_IO_APIC
1693 	 * We need clear_IO_APIC before enabling error vector
1694 	 */
1695 	if (!skip_ioapic_setup && nr_ioapics)
1696 		enable_IO_APIC();
1697 #endif
1698 
1699 	end_local_APIC_setup();
1700 
1701 #ifdef CONFIG_X86_IO_APIC
1702 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1703 		setup_IO_APIC();
1704 	else {
1705 		nr_ioapics = 0;
1706 		localise_nmi_watchdog();
1707 	}
1708 #else
1709 	localise_nmi_watchdog();
1710 #endif
1711 
1712 	x86_init.timers.setup_percpu_clockev();
1713 #ifdef CONFIG_X86_64
1714 	check_nmi_watchdog();
1715 #endif
1716 
1717 	return 0;
1718 }
1719 
1720 /*
1721  * Local APIC interrupts
1722  */
1723 
1724 /*
1725  * This interrupt should _never_ happen with our APIC/SMP architecture
1726  */
1727 void smp_spurious_interrupt(struct pt_regs *regs)
1728 {
1729 	u32 v;
1730 
1731 	exit_idle();
1732 	irq_enter();
1733 	/*
1734 	 * Check if this really is a spurious interrupt and ACK it
1735 	 * if it is a vectored one.  Just in case...
1736 	 * Spurious interrupts should not be ACKed.
1737 	 */
1738 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1739 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1740 		ack_APIC_irq();
1741 
1742 	inc_irq_stat(irq_spurious_count);
1743 
1744 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1745 	pr_info("spurious APIC interrupt on CPU#%d, "
1746 		"should never happen.\n", smp_processor_id());
1747 	irq_exit();
1748 }
1749 
1750 /*
1751  * This interrupt should never happen with our APIC/SMP architecture
1752  */
1753 void smp_error_interrupt(struct pt_regs *regs)
1754 {
1755 	u32 v, v1;
1756 
1757 	exit_idle();
1758 	irq_enter();
1759 	/* First tickle the hardware, only then report what went on. -- REW */
1760 	v = apic_read(APIC_ESR);
1761 	apic_write(APIC_ESR, 0);
1762 	v1 = apic_read(APIC_ESR);
1763 	ack_APIC_irq();
1764 	atomic_inc(&irq_err_count);
1765 
1766 	/*
1767 	 * Here is what the APIC error bits mean:
1768 	 * 0: Send CS error
1769 	 * 1: Receive CS error
1770 	 * 2: Send accept error
1771 	 * 3: Receive accept error
1772 	 * 4: Reserved
1773 	 * 5: Send illegal vector
1774 	 * 6: Received illegal vector
1775 	 * 7: Illegal register address
1776 	 */
1777 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1778 		smp_processor_id(), v , v1);
1779 	irq_exit();
1780 }
1781 
1782 /**
1783  * connect_bsp_APIC - attach the APIC to the interrupt system
1784  */
1785 void __init connect_bsp_APIC(void)
1786 {
1787 #ifdef CONFIG_X86_32
1788 	if (pic_mode) {
1789 		/*
1790 		 * Do not trust the local APIC being empty at bootup.
1791 		 */
1792 		clear_local_APIC();
1793 		/*
1794 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1795 		 * local APIC to INT and NMI lines.
1796 		 */
1797 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1798 				"enabling APIC mode.\n");
1799 		imcr_pic_to_apic();
1800 	}
1801 #endif
1802 	if (apic->enable_apic_mode)
1803 		apic->enable_apic_mode();
1804 }
1805 
1806 /**
1807  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1808  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1809  *
1810  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1811  * APIC is disabled.
1812  */
1813 void disconnect_bsp_APIC(int virt_wire_setup)
1814 {
1815 	unsigned int value;
1816 
1817 #ifdef CONFIG_X86_32
1818 	if (pic_mode) {
1819 		/*
1820 		 * Put the board back into PIC mode (has an effect only on
1821 		 * certain older boards).  Note that APIC interrupts, including
1822 		 * IPIs, won't work beyond this point!  The only exception are
1823 		 * INIT IPIs.
1824 		 */
1825 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1826 				"entering PIC mode.\n");
1827 		imcr_apic_to_pic();
1828 		return;
1829 	}
1830 #endif
1831 
1832 	/* Go back to Virtual Wire compatibility mode */
1833 
1834 	/* For the spurious interrupt use vector F, and enable it */
1835 	value = apic_read(APIC_SPIV);
1836 	value &= ~APIC_VECTOR_MASK;
1837 	value |= APIC_SPIV_APIC_ENABLED;
1838 	value |= 0xf;
1839 	apic_write(APIC_SPIV, value);
1840 
1841 	if (!virt_wire_setup) {
1842 		/*
1843 		 * For LVT0 make it edge triggered, active high,
1844 		 * external and enabled
1845 		 */
1846 		value = apic_read(APIC_LVT0);
1847 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1848 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1849 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1850 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1851 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1852 		apic_write(APIC_LVT0, value);
1853 	} else {
1854 		/* Disable LVT0 */
1855 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1856 	}
1857 
1858 	/*
1859 	 * For LVT1 make it edge triggered, active high,
1860 	 * nmi and enabled
1861 	 */
1862 	value = apic_read(APIC_LVT1);
1863 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1864 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1865 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1866 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1867 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1868 	apic_write(APIC_LVT1, value);
1869 }
1870 
1871 void __cpuinit generic_processor_info(int apicid, int version)
1872 {
1873 	int cpu;
1874 
1875 	/*
1876 	 * Validate version
1877 	 */
1878 	if (version == 0x0) {
1879 		pr_warning("BIOS bug, APIC version is 0 for CPU#%d! "
1880 			   "fixing up to 0x10. (tell your hw vendor)\n",
1881 				version);
1882 		version = 0x10;
1883 	}
1884 	apic_version[apicid] = version;
1885 
1886 	if (num_processors >= nr_cpu_ids) {
1887 		int max = nr_cpu_ids;
1888 		int thiscpu = max + disabled_cpus;
1889 
1890 		pr_warning(
1891 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1892 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1893 
1894 		disabled_cpus++;
1895 		return;
1896 	}
1897 
1898 	num_processors++;
1899 	cpu = cpumask_next_zero(-1, cpu_present_mask);
1900 
1901 	if (version != apic_version[boot_cpu_physical_apicid])
1902 		WARN_ONCE(1,
1903 			"ACPI: apic version mismatch, bootcpu: %x cpu %d: %x\n",
1904 			apic_version[boot_cpu_physical_apicid], cpu, version);
1905 
1906 	physid_set(apicid, phys_cpu_present_map);
1907 	if (apicid == boot_cpu_physical_apicid) {
1908 		/*
1909 		 * x86_bios_cpu_apicid is required to have processors listed
1910 		 * in same order as logical cpu numbers. Hence the first
1911 		 * entry is BSP, and so on.
1912 		 */
1913 		cpu = 0;
1914 	}
1915 	if (apicid > max_physical_apicid)
1916 		max_physical_apicid = apicid;
1917 
1918 #ifdef CONFIG_X86_32
1919 	switch (boot_cpu_data.x86_vendor) {
1920 	case X86_VENDOR_INTEL:
1921 		if (num_processors > 8)
1922 			def_to_bigsmp = 1;
1923 		break;
1924 	case X86_VENDOR_AMD:
1925 		if (max_physical_apicid >= 8)
1926 			def_to_bigsmp = 1;
1927 	}
1928 #endif
1929 
1930 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1931 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1932 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1933 #endif
1934 
1935 	set_cpu_possible(cpu, true);
1936 	set_cpu_present(cpu, true);
1937 }
1938 
1939 int hard_smp_processor_id(void)
1940 {
1941 	return read_apic_id();
1942 }
1943 
1944 void default_init_apic_ldr(void)
1945 {
1946 	unsigned long val;
1947 
1948 	apic_write(APIC_DFR, APIC_DFR_VALUE);
1949 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
1950 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
1951 	apic_write(APIC_LDR, val);
1952 }
1953 
1954 #ifdef CONFIG_X86_32
1955 int default_apicid_to_node(int logical_apicid)
1956 {
1957 #ifdef CONFIG_SMP
1958 	return apicid_2_node[hard_smp_processor_id()];
1959 #else
1960 	return 0;
1961 #endif
1962 }
1963 #endif
1964 
1965 /*
1966  * Power management
1967  */
1968 #ifdef CONFIG_PM
1969 
1970 static struct {
1971 	/*
1972 	 * 'active' is true if the local APIC was enabled by us and
1973 	 * not the BIOS; this signifies that we are also responsible
1974 	 * for disabling it before entering apm/acpi suspend
1975 	 */
1976 	int active;
1977 	/* r/w apic fields */
1978 	unsigned int apic_id;
1979 	unsigned int apic_taskpri;
1980 	unsigned int apic_ldr;
1981 	unsigned int apic_dfr;
1982 	unsigned int apic_spiv;
1983 	unsigned int apic_lvtt;
1984 	unsigned int apic_lvtpc;
1985 	unsigned int apic_lvt0;
1986 	unsigned int apic_lvt1;
1987 	unsigned int apic_lvterr;
1988 	unsigned int apic_tmict;
1989 	unsigned int apic_tdcr;
1990 	unsigned int apic_thmr;
1991 } apic_pm_state;
1992 
1993 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1994 {
1995 	unsigned long flags;
1996 	int maxlvt;
1997 
1998 	if (!apic_pm_state.active)
1999 		return 0;
2000 
2001 	maxlvt = lapic_get_maxlvt();
2002 
2003 	apic_pm_state.apic_id = apic_read(APIC_ID);
2004 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2005 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2006 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2007 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2008 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2009 	if (maxlvt >= 4)
2010 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2011 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2012 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2013 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2014 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2015 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2016 #ifdef CONFIG_X86_THERMAL_VECTOR
2017 	if (maxlvt >= 5)
2018 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2019 #endif
2020 
2021 	local_irq_save(flags);
2022 	disable_local_APIC();
2023 
2024 	if (intr_remapping_enabled)
2025 		disable_intr_remapping();
2026 
2027 	local_irq_restore(flags);
2028 	return 0;
2029 }
2030 
2031 static int lapic_resume(struct sys_device *dev)
2032 {
2033 	unsigned int l, h;
2034 	unsigned long flags;
2035 	int maxlvt;
2036 	int ret = 0;
2037 	struct IO_APIC_route_entry **ioapic_entries = NULL;
2038 
2039 	if (!apic_pm_state.active)
2040 		return 0;
2041 
2042 	local_irq_save(flags);
2043 	if (intr_remapping_enabled) {
2044 		ioapic_entries = alloc_ioapic_entries();
2045 		if (!ioapic_entries) {
2046 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2047 			ret = -ENOMEM;
2048 			goto restore;
2049 		}
2050 
2051 		ret = save_IO_APIC_setup(ioapic_entries);
2052 		if (ret) {
2053 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2054 			free_ioapic_entries(ioapic_entries);
2055 			goto restore;
2056 		}
2057 
2058 		mask_IO_APIC_setup(ioapic_entries);
2059 		mask_8259A();
2060 	}
2061 
2062 	if (x2apic_mode)
2063 		enable_x2apic();
2064 	else {
2065 		/*
2066 		 * Make sure the APICBASE points to the right address
2067 		 *
2068 		 * FIXME! This will be wrong if we ever support suspend on
2069 		 * SMP! We'll need to do this as part of the CPU restore!
2070 		 */
2071 		rdmsr(MSR_IA32_APICBASE, l, h);
2072 		l &= ~MSR_IA32_APICBASE_BASE;
2073 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2074 		wrmsr(MSR_IA32_APICBASE, l, h);
2075 	}
2076 
2077 	maxlvt = lapic_get_maxlvt();
2078 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2079 	apic_write(APIC_ID, apic_pm_state.apic_id);
2080 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2081 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2082 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2083 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2084 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2085 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2086 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2087 	if (maxlvt >= 5)
2088 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2089 #endif
2090 	if (maxlvt >= 4)
2091 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2092 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2093 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2094 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2095 	apic_write(APIC_ESR, 0);
2096 	apic_read(APIC_ESR);
2097 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2098 	apic_write(APIC_ESR, 0);
2099 	apic_read(APIC_ESR);
2100 
2101 	if (intr_remapping_enabled) {
2102 		reenable_intr_remapping(x2apic_mode);
2103 		unmask_8259A();
2104 		restore_IO_APIC_setup(ioapic_entries);
2105 		free_ioapic_entries(ioapic_entries);
2106 	}
2107 restore:
2108 	local_irq_restore(flags);
2109 
2110 	return ret;
2111 }
2112 
2113 /*
2114  * This device has no shutdown method - fully functioning local APICs
2115  * are needed on every CPU up until machine_halt/restart/poweroff.
2116  */
2117 
2118 static struct sysdev_class lapic_sysclass = {
2119 	.name		= "lapic",
2120 	.resume		= lapic_resume,
2121 	.suspend	= lapic_suspend,
2122 };
2123 
2124 static struct sys_device device_lapic = {
2125 	.id	= 0,
2126 	.cls	= &lapic_sysclass,
2127 };
2128 
2129 static void __cpuinit apic_pm_activate(void)
2130 {
2131 	apic_pm_state.active = 1;
2132 }
2133 
2134 static int __init init_lapic_sysfs(void)
2135 {
2136 	int error;
2137 
2138 	if (!cpu_has_apic)
2139 		return 0;
2140 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2141 
2142 	error = sysdev_class_register(&lapic_sysclass);
2143 	if (!error)
2144 		error = sysdev_register(&device_lapic);
2145 	return error;
2146 }
2147 
2148 /* local apic needs to resume before other devices access its registers. */
2149 core_initcall(init_lapic_sysfs);
2150 
2151 #else	/* CONFIG_PM */
2152 
2153 static void apic_pm_activate(void) { }
2154 
2155 #endif	/* CONFIG_PM */
2156 
2157 #ifdef CONFIG_X86_64
2158 
2159 static int __cpuinit apic_cluster_num(void)
2160 {
2161 	int i, clusters, zeros;
2162 	unsigned id;
2163 	u16 *bios_cpu_apicid;
2164 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2165 
2166 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2167 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2168 
2169 	for (i = 0; i < nr_cpu_ids; i++) {
2170 		/* are we being called early in kernel startup? */
2171 		if (bios_cpu_apicid) {
2172 			id = bios_cpu_apicid[i];
2173 		} else if (i < nr_cpu_ids) {
2174 			if (cpu_present(i))
2175 				id = per_cpu(x86_bios_cpu_apicid, i);
2176 			else
2177 				continue;
2178 		} else
2179 			break;
2180 
2181 		if (id != BAD_APICID)
2182 			__set_bit(APIC_CLUSTERID(id), clustermap);
2183 	}
2184 
2185 	/* Problem:  Partially populated chassis may not have CPUs in some of
2186 	 * the APIC clusters they have been allocated.  Only present CPUs have
2187 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2188 	 * Since clusters are allocated sequentially, count zeros only if
2189 	 * they are bounded by ones.
2190 	 */
2191 	clusters = 0;
2192 	zeros = 0;
2193 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2194 		if (test_bit(i, clustermap)) {
2195 			clusters += 1 + zeros;
2196 			zeros = 0;
2197 		} else
2198 			++zeros;
2199 	}
2200 
2201 	return clusters;
2202 }
2203 
2204 static int __cpuinitdata multi_checked;
2205 static int __cpuinitdata multi;
2206 
2207 static int __cpuinit set_multi(const struct dmi_system_id *d)
2208 {
2209 	if (multi)
2210 		return 0;
2211 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2212 	multi = 1;
2213 	return 0;
2214 }
2215 
2216 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2217 	{
2218 		.callback = set_multi,
2219 		.ident = "IBM System Summit2",
2220 		.matches = {
2221 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2222 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2223 		},
2224 	},
2225 	{}
2226 };
2227 
2228 static void __cpuinit dmi_check_multi(void)
2229 {
2230 	if (multi_checked)
2231 		return;
2232 
2233 	dmi_check_system(multi_dmi_table);
2234 	multi_checked = 1;
2235 }
2236 
2237 /*
2238  * apic_is_clustered_box() -- Check if we can expect good TSC
2239  *
2240  * Thus far, the major user of this is IBM's Summit2 series:
2241  * Clustered boxes may have unsynced TSC problems if they are
2242  * multi-chassis.
2243  * Use DMI to check them
2244  */
2245 __cpuinit int apic_is_clustered_box(void)
2246 {
2247 	dmi_check_multi();
2248 	if (multi)
2249 		return 1;
2250 
2251 	if (!is_vsmp_box())
2252 		return 0;
2253 
2254 	/*
2255 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2256 	 * not guaranteed to be synced between boards
2257 	 */
2258 	if (apic_cluster_num() > 1)
2259 		return 1;
2260 
2261 	return 0;
2262 }
2263 #endif
2264 
2265 /*
2266  * APIC command line parameters
2267  */
2268 static int __init setup_disableapic(char *arg)
2269 {
2270 	disable_apic = 1;
2271 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2272 	return 0;
2273 }
2274 early_param("disableapic", setup_disableapic);
2275 
2276 /* same as disableapic, for compatibility */
2277 static int __init setup_nolapic(char *arg)
2278 {
2279 	return setup_disableapic(arg);
2280 }
2281 early_param("nolapic", setup_nolapic);
2282 
2283 static int __init parse_lapic_timer_c2_ok(char *arg)
2284 {
2285 	local_apic_timer_c2_ok = 1;
2286 	return 0;
2287 }
2288 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2289 
2290 static int __init parse_disable_apic_timer(char *arg)
2291 {
2292 	disable_apic_timer = 1;
2293 	return 0;
2294 }
2295 early_param("noapictimer", parse_disable_apic_timer);
2296 
2297 static int __init parse_nolapic_timer(char *arg)
2298 {
2299 	disable_apic_timer = 1;
2300 	return 0;
2301 }
2302 early_param("nolapic_timer", parse_nolapic_timer);
2303 
2304 static int __init apic_set_verbosity(char *arg)
2305 {
2306 	if (!arg)  {
2307 #ifdef CONFIG_X86_64
2308 		skip_ioapic_setup = 0;
2309 		return 0;
2310 #endif
2311 		return -EINVAL;
2312 	}
2313 
2314 	if (strcmp("debug", arg) == 0)
2315 		apic_verbosity = APIC_DEBUG;
2316 	else if (strcmp("verbose", arg) == 0)
2317 		apic_verbosity = APIC_VERBOSE;
2318 	else {
2319 		pr_warning("APIC Verbosity level %s not recognised"
2320 			" use apic=verbose or apic=debug\n", arg);
2321 		return -EINVAL;
2322 	}
2323 
2324 	return 0;
2325 }
2326 early_param("apic", apic_set_verbosity);
2327 
2328 static int __init lapic_insert_resource(void)
2329 {
2330 	if (!apic_phys)
2331 		return -1;
2332 
2333 	/* Put local APIC into the resource map. */
2334 	lapic_resource.start = apic_phys;
2335 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2336 	insert_resource(&iomem_resource, &lapic_resource);
2337 
2338 	return 0;
2339 }
2340 
2341 /*
2342  * need call insert after e820_reserve_resources()
2343  * that is using request_resource
2344  */
2345 late_initcall(lapic_insert_resource);
2346